kardiomyocyterna

Kardiomyocyterna, also known as cardiac muscle cells or cardiomyocytes, are specialized cells responsible for the contractile function of the heart. These cells form the muscular tissue of the myocardium, the heart's main muscular layer, and are essential for enabling the rhythmic contractions necessary for blood circulation.

Structurally, cardiomyocytes are elongated, cylindrical cells with a centrally located nucleus, although some may contain multiple nuclei. They are characterized by a high density of mitochondria, which support the substantial energy demands of continuous heart activity. The cells are interconnected via intercalated discs—complex junctions that facilitate synchronized contractions by allowing rapid electrical impulse transmission.

Cardiomyocytes contain specialized contractile proteins, primarily actin and myosin, organized into sarcomeres—the fundamental units of muscle contraction. These cells exhibit involuntary contractile activity, regulated by the autonomic nervous system and intrinsic cardiac conduction system, including the sinoatrial (SA) node and atrioventricular (AV) node.

The development of cardiomyocytes occurs primarily during embryogenesis, originating from mesodermal progenitors. Most adult cardiomyocytes are considered terminally differentiated, with limited regenerative capacity, which has implications for heart repair after injury such as myocardial infarction.

Pathological conditions affecting cardiomyocytes include hypertrophy, hypertrophic cardiomyopathy, and various forms of cardiomyopathy, which can impair the heart's ability to pump blood efficiently. Understanding the structure, function, and pathology of cardiomyocytes is crucial in cardiovascular medicine and research aimed at treating heart diseases.